Double vs single primary tooth extraction in interceptive treatment of palatally displaced canines

To compare the impact of primary canine and primary first molar extractions with extractions of only the primary canine regarding correction of palatally displaced canines (PDCs).

Thirty-two children aged 9.5-13.5 years with 48 PDCs were randomly allocated to either the double-extraction group (DEG) or single-extraction group (SEG). Clinical and radiographic examinations were performed at baseline and at 6-month intervals until the canine emerged or orthodontic treatment was started. Outcome measures were: emergence of maxillary canine (yes/no), emergence of maxillary canine into a favorable position (yes/no), and maxillary canine positional change (angulation and sector). Factors influencing PDC emergence were analyzed using logistic regression.

In the DEG, 64% (16/25) of canines emerged into the oral cavity vs 78% (18/23) in the SEG (P = .283). Favorable PDC position at trial end was seen in 64% (16/25) of the DEG vs 57% (13/23) of the SEG (P = .600). Significant distal movement of PDCs was recorded in the DEG and SEG, though no significant difference was observed between groups. Significant predictors of canine emergence were initial canine angulation (Angle A) (P = .008) and space conditions at T0 (P = .030).

Double or single primary tooth extraction procedures are equivalent in supporting PDC eruption into the oral cavity and into a favorable position in the dental arch. Initial canine angulation and space assessments may be used as predictors of successful PDC eruption.